Researchers in Scotland conducted a pilot study to measure the immediate electrophysical and cognitive effects of heading, a routine soccer (football in the United Kingdom) activity. Heading has been associated with subconcussive head trauma.1,2

Amateur soccer players were recruited from local soccer clubs and universities for inclusion in the study. Exclusion criteria included the following: history of head injury causing loss of consciousness, history of a neurologic condition, history of concussion within the past 12 months, family history of epilepsy, and the use of psychoactive or prescription drugs. Each participant underwent a heading protocol that consisted of heading a standard soccer ball at standardized speeds. The primary outcome measure was corticomotor inhibition, which was measured using transcranial magnetic stimulation. This measurement consisted of quantifying the cortical silent period after motor-evoked potentials were delivered to the appropriate primary motor complex. Secondary outcome measures included reaction time, paired associate learning, spatial working memory, attention task switching, and rapid visual processing, all of which were assessed based on the Cambridge Neuropsychological Test Automated Battery. Measurements were taken at baseline and immediately after, 24 hours after, 48 hours after, and 14 days after the heading protocol.